Saving $150 per month is a daunting task for most Americans. But what about stashing away five bucks a day?

No problem, say nearly 30 percent of customers of Acorns, a mobile-first savings app that rounds up spare change from purchases made with credit or debit cards and invests it in diversified portfolios built with low-cost exchange traded funds.

But there's a catch: Saving $5 daily adds up to $150 a month. Yet just 7 percent of account holders setting up an automatic "recurring" savings plan on Acorns' app, when given a choice, selected the $150 a month option.

What explains this disconnect? It’s the way the human mind is wired when it comes to money.

A new initiative from Acorns announced Thursday, dubbed the Money Lab, will marry proven insights from the emerging field of behavioral finance with digital technology to try to help Americans make better financial decisions.

Leading the Acorns’ initiative will be Shlomo Benartzi, professor and co-founder of the Behavioral Decision-Making group at UCLA’s Anderson School of Management.

Benartzi explains the psychological reasons why saving a little bit of money every day seems a lot easier to people than committing to a larger lump sum: “Saving $5 a day makes us think about skipping a Starbucks latte, and that seems doable, while $150 a month makes us think about car payments, which is a much more daunting amount to give up.”

Indeed just as public-TV fundraisers may stress that you can help fund great programming by contributing say, just $7 a week (rather than hitting you up for $365 for a full year in one transaction), the financial industry is also "framing" investment choices in different ways to get greater participation and buy-in from potential savers.

"Now we're focused on how we can combine insights of psychology and economics to create an entire financial system that helps people save and invest," says Noah Kerner, CEO of Acorns, an app with 4 million U.S. accounts, nearly two-thirds of which are held by Americans younger than 35.

Kerner stresses that the Money Lab isn't a product feature per se, but rather an initiative that looks to build on the "brain trust" of the behavioral finance research community and help Acorns come up with innovative ways to help their clients become better savers and investors.

A simple "nudge," or intervention that gets people to alter their financial behavior in a positive way, can have a powerful effect on investment outcomes, Kerner says.

In the real-world example of framing the savings option as setting aside $5 per day or $150 per month, the participation rate was four times greater for those opting for socking a way a small sum each day.

And, more important, people making $25,000 were just as likely as those earning $100,000 to commit to the daily savings rate of $5. Those findings suggest that it's possible to "close the savings gap" between lower- and upper-income earners, says Kerner.

Kerner says that the adoption rate of the app's "recurring" savings feature has gone from a roughly 20 percent usage to 65 percent simply by adding the "simple suggestion" of having five bucks a day swept into an investment account.

"We're already seeing strong success," Kerner says.

More experiments driven by the behavioral economics team led by Benartzi are currently underway. There's already been a call for real-life field experiments on how to "reduce consumer spending" and get consumers to "spend smarter."

"We will take the findings and implement them into our products," the Acorns CEO said.